PAH degradation by UV/H2O2 in perfluorinated surfactant solutions

Polycyclic aromatic hydrocarbons (PAHs) solubilized in perfluorinated surfa ctant (PFS) solutions were degraded by direct photolysis and UV/H2O2 proces s. The subsequent recovery and reuse of these surfactant solutions were als o demonstrated. Phenanthrene and pyrene were selected as representative PAH s and an anionic PFS; ammonium perfluorooctanoate (APFO) was used, In our e xperiments, micellar APFO solutions retarded the phenanthrene photolysis an d enhanced the pyrene photolysis. The results indicate that the photochemic al reactivity of compound in micelles is strongly dependent on specific pro perties of the solubilizate, possibly due to the different excited state be haviors of compound. UV/H2O2 process exhibits a greatly enhanced rate of PA H photolysis in both water and APFO compared to direct photolysis, indicati ng that hydroxyl radicals may be generated or penetrated at the sites of PA Hs solubilized in the micelles. Additionally, a smaller rate enhancement by UV/H2O2 in micelles than in water suggests that micelles provide some degr ee of protection from hydroxyl radical attack. The possibility of recovery and reuse of PFS has been demonstrated by measuring the solubilizing capaci ty of APFO after direct photolysis and UV/H2O2 process. Overall, this study demonstrates UV/H2O2 process can be an effective treatment method for not only PAH degradation but also surfactant recovery and reuse. (C) 2001 Elsev ier Science Ltd. All rights reserved.